Foldable television antenna



Marcli 23, 1954 G. G. WENTWORTH 2,673,295

FOLDABLE TELEVISION ANTENNA Filed Sept. 11, 1950 2 Sheets-Sheet 1 Inventor Gerald G. Wen/worth g WWW M S March 23, 1954 G, G. WENTWORTH FOLDABLE TELEVISION ANTENNA 2 Sheets-Sheet 2 Filed Sept. 11 1950 \.N an m m R a S m R m 9b In UPI/l0! Gerald 6. Wen/worth Patented Mar. 23, 1954 UNITED STATES PATENT OFFICE Claims.

This invention relates to antennae of the dipole type for the reception of short waves or ultra short waves, such as used for FM or television signals and it has for its main object to provide an adjustable, foldable and portable antenna structure or antenna, array which may be carried by an operator or service man, the operating parts of which are so mounted within the supporting parts that they occupy little space when folded, while they may be brought into operating position by V a simple manipulation so that they are practically ready for operation without any additional mounting or other activity.

As is well known in this art one of the most simple and effective antennae for receiving television and FM signals is the dipole antenna which is preferably used in connection with a reflector or with a director and which consists of two metal rods which are pointing in different directions and the length of which is related tothe wave lengths to be received. These two rods are insulated from each other and in many cases are aligned and connected with the feed lines at their adjacent ends.

The dipole antenna is directional insofar as its position is related to the plane of polarization of the waves which are received and also insofar as the antenna should be responsive to incoming waves only but should not pick up reflected waves coming from other directions which are reflected by objects near the antenna. To exclude reflections from stationary objects in the vicinity, the antenna consists usually of parts or elements which are mounted on the spot and are bolted together and which permit the mounting of the antenna array in different directions. The building up or mounting of the antenna on the spot on which the installation is made is moreover also necessary because a dipole antem1a on its mast has dimensions in two or in three directions which render transportation in a mounted condition rather difficult. Therefore, the mounting of an antenna is a rather time consuming job, especially as attention has not only to be paid to the electrical part of the installation but also to the mechanical strength of the antenna structure or array to resist wind pressure and the like and moreover the insulation should be suchthat it should not be disturbed by atmospheric conditions or by other factors.

It is therefore a major advantage even in the case of a stationary dipole antenna to be able to mount a complete antenna structure or array which has merely to be placed on the mast and pointed to a given direction and which is reasonably free from interference as this reduces materially the labor necessary for the erection of the antenna.

It is moreover, of course, especially desirable to use such a complete antenna structure in connection with portable or field stations which change their locations from time to time.

It will be clear that easy transportation of an antenna structure is only possible if the antenna structure has an extension which is limited to a single direction while the structure is of negligible dimensions in all other directions. This antenna structure must then be transformed into one in which all the parts are made to extend into those directions which are necessary for operation by a small number of simple manipulations which are easy to perform and which do not require any special skill.

According to the invention the support which also forms the spacing bar, spacing the antenna from the reflector, and which is usually also the member which is attached to the mast of the antenna structure, forms a. case or housing for foldable antenna and reflector rods which are arranged within said case or housing already in proper mechanical and electrical relationship and which are movable along fixed tracks from their folded positions into their operative or receiving positions in which they spread outwardly. The manipulation to be performed is thus a simple and well defined manipulation and it consists merely in moving the folded members from one position within the housing .or case into another position and in fixing them in this position. By using telescoping antenna and reflector members and a suitable attachment of the spacer bar to the mast the direction of the dipole rods and their adjustment for the desired frequency may be carried out in a most simple and effective manner.

The invention is described with reference to the accompanying drawings which illustrate one embodiment of the invention by way of example. It is, however, to be understood that the specification and the drawings do not intend to give a survey of the embodiments of the invention and that the example shown merely tends to illustrate the principle of the invention and the best mode of applying the principle. A departure from the example illustrated in the drawings is therefore not necessarily a departure from the principle of the invention.

' In the drawings:

Figure 1 is a perspective view ofthe antenna structure when in its operative position;

Figure 2 is a sectional plan view of the antenna structure in a folded position, the section being taken along line 22 of Figure 3;

Figure 3 is an elevational sectional view of the antenna structure when in a folded position, the section being taken along line 33 of Figure 2;

Figure 4 is a sectional plan view of one end of the antenna structure with the antenna rods in their operative position, the section being taken along line 44 of Figure 1;

Figure 5 is a sectional elevational view of the antenna structure when in a folded position, the section being taken along line 5-5 of Figure 3;

Figure 6 is an elevational view of a detail section, the section being taken along line 6-6 of Figure 4;

Figure 7 is an elevational cross sectional view of the antenna when mounted on the mast, the section being taken along line '|'I of Figure 1;

Figure 8 is a perspective view of the hinge bolt and plate used for hinging the ends of the foldable antenna or reflector rods; and

Figure 9 is a sectional elevational view of a reinforced supporting and spacer member.

According to the invention the antenna structure essentially comprises a spacing and supporting member l3 which also constitutes the means for holding the antenna on the mast and which forms the housing accommodating folded dipole and reflector rods. The antenna and reflector rods |2 are mechanically joined and hinged to each other so as to make them foldable and they are provided with means for fixing them in a folded and in an operative position. Insulating means are moreover provided on the hinges and on the casing in order to insulate the antenna dipoles from each other and from the reflector.

As seen from Figures 1, 4, 5 and '7, the main supporting and spacer member ID consists of a hollow, elongated, prismatic body of substantially closed square or oblong cross section, open at its ends, and which is of a length somewhat exceeding the distance between the dipole antenna H and its reflector l2. Said body is provided with an elongated slot |4 in its top wall l6 and with a further elongated slot H in its bottom wall l8. The longitudinal slots 14 and I1 extend lengthwise along the bottom and top of said member without reaching the ends. Near the ends of the body it] the side walls l9 and 2| are provided with short parallel slots 20, 22; 24, 25, the slots at each end being arranged in the same horizontal plane but the slots on both ends being arranged in different planes at diiferent distances from the bottom wall.

The central part of the supporting and spacing member It is bolted or riveted to a bracket member 26 comprising two plates 21, 28 which are offset with respect to each other, one of which, 21, being fixed to the supporting and spacing member l0 while the other plate is provided with a pair of holes through which the U-shaped bolt 25 fixing the antenna structure on the mast 30 may pass.

The offsetting of the two plates 2'! and 28 serves the purpose of permitting a fixation of the structure on the mast 39 in any position along said mast so that several antennae units may be stacked and may be arranged one above the other on the mast.

The dipole H is a foldable structure with two hinged dipole rods or tubes 3|, 32 which are hinged and which may therefore be folded so as to occupy positions alongside of each other in which state they may be retracted and held within the hollow interior of the member I0. Within the tubular rods 3|, 32 extension rods 33, 34 may be held in order to produce the required length of the dipole for the reception of a desired frequency in the event that the dipole has to be longer than the supporting and spacing member Hi. This length, as well known, depends on the frequency which also determines the distance between the members and |2.

The dipole rods or tubes 3|, 32 are thus of the telescoping type and the rods 33, 34 may be pulled out to a different extent in order to adjust them to different frequencies.

The dipole tubes or rods 3|, 32 are held in socket and hinge members 35, 36 one of which members is shown in perspective in Figure 8. The hinge and socket member comprises a screw threaded bolt 31 which engages the internally threaded ends of the dipole rods 3|, S2 respec tively, as seen in Figure 3. The hinge plates 38, 39 are provided with an eye 43, 4| respectively, and with a shoulder portion having a shoulder 42 which may be solidary with the bolt 31.

Through the eyes 40, 4| of the hinge plates 38, 39 of the two tubes or rods 3 I, 32 a screw threaded spindle 44 passes which carries an insulating sleeve 45, provided with a flange 4E. The spindle 44 passes through the slot M and projects to the outside. A nut is provided on one side of the spindle while the upper side which projects through the slot is provided with a wing nut 48, An insulating washer 49 surrounding the sleeve 45 prevents contact between the spindle and the supporting and spacing bar ID.

A further insulating washer 50 is inserted between the two hinge plates and a still further insulated washer 5| is inserted between the upper hinge plate 38 and the upper wall |6 of the member ID. The two dipole rods or tubes are thus completely insulated from each other and from the member ID.

Each of the two dipole rods or tubes 3|, 32 carries a terminal post 52 for the attachment of the feed line of the antenna leading to the receiver.

In order to prevent contact between the dipole rods 3|, 32 and the side walls |9, 2| of the member ||l when the dipole is in operative position the slots 20, 22 in the side walls l9, 2| are wider than the dipole rods or tubes and insulated slotted plates 54, 55 are fixed on the ends of the side walls l9, 2| on one side of the supporting and spacing member l0 by means of rivets or bolts which cover the slotted portions of the member ID. The slots 64 of these plates 54, 55 are aligned with those of the member I0 but are somewhat narrower and are just of sufficient width to permit the passage of the dipole rods 3|, 32. Near the ends of said slots enlarged rest portions are provided which serve as a rest for the dipole rods when in operative position. The dipole rods will therefore only come into contact with the insulated plates, while they are prevented from coming into contact with the member |0.

Near the end of the spacing and supporting member Hl a spacing wedge 56 is arrange-d which turns its sharp edge and its inclined wedge faces towards the interior of the said supporting and spacing member and which is held in a substan tially vertical position by means of screw bolts 58 fastened in the top and bottom walls It and 8, respectively.

Obviously, when the wing nut 48 is unscrewed the hinge of the dipole rodsformed by the spindle 44 and the hinge plates 38, 39 may slide along amazes the slot l4 until it reaches the far end of the member ID. The two dipole rods are folded as shown in Figure 2 during such movement and so folded they may be housed within the hollow interior of the member ID. The shoulders 42 on the hinge plates 38, 39 hold the dipole rods when folded at a certain distance. When the spindle 44 together with the dipole rods is moved outwardly into its operative position the two dipole rods pass on the two sides of the wedge and iinally when the spindle M nears the endposition the dipole rods are spread and aligned and finally enter the slots 20, 22 sliding within the slot 64 of the insulated plates 54 and 55 and they come to rest in the enlarged upper end portions 6! when they reach the position shown in Figure 1.

In order to fix the dipole rods in this position small springs 62 may be pivoted at (i3 on the insulated plates 54, 55 which press the dipole rods 3!, 32 against the upper edge of the slot 64 when they reach the ends of the slot so that they will be held in the enlarged portions SI and will be fixed in this position of rest.

It has already been mentioned that the two slots 2!], 22 are not in the same horizontal plane inwhich the slots 24, 25 are arranged. It will therefore be clear that the dipole rods 3 I, 32 when folded and when moved into the interior of the supporting and spacing member will occupy merely the upper half of the said hollow member and will leave the lower half free to accommodate a, second pair of foldable rods.

This second pair of rods is formed by the reflector rods 64, 65 which are constructed and held in a manner which is similar to that already described in connection with the dipole rods and which therefore need not be described in detail. There is however the difference that the reflector rods need not be insulated from each other or from the member It. Therefore the said rods have internally screwed ends connected with hinge members d8, 69 similar to the hinge members 35, 35, with eyes through which the spindle 15 passes which projects through the slot I! and carries a wing nut 15 on the projecting end. The spindle and the wing nut together with the hinge members may again slide along the slot H. While washers l1, l8 may be arranged in order to cover the hinge plates 68, 69 they need not be insulating, as the hinge plates are in contact with the spindle. Again, near the rear end of the supporting and spacing member Ill a spacing wedge 51 may be arranged which is held by the bolt 59 passing through the top and bottom walls and which deflects and spreads the folded reflector rods when the spindle T5 the wing nut 16 and the hinge members are moved from the position shown in Figure 3 towards the operative position which is shown in Figure l.

The reflector rods 64, 65 enter the slots 24 and 25 when the spindle, wing nut and hinge plates have been moved close to the end position. The slots 2% and 25 are in this case provided with enlarged resting positions near their inner ends which hold the reflector rods when spread, while a spring 80 similar to spring 52 presses the f'said reflector rods into these enlarged resting ends 19 of the slots 25, 24.

When the supporting and spacing member Ill is of great length, a reinforcement is preferably provided in order to avoid a special construction or an excessive thickness of the wall which might add to the weight.

As shown in Figure 9, the slots in this fgase may have raised or stepped side walls 8| and'an "6 inner reinforcing member 82"is"preferably arranged in the middle of the supporting and spacing member H) which reinfor'cesthe portion of the member which is attached to'the bracket 26 on the outside. 7

It has already been mentioned that the dipole rods and the reflector rods may consist of a number of telescoping tubular rods 3|, 33, 32, 34, 64, 6 6, 65, 61 when the standard length required for the intended frequency is larger than the length which can be accommodated within the member ID. A plurality of telescoping rods may be arranged and preferably the inner rods 33, 34 are provided with markers or with a scale in order to facilitatetheir adjustment for a desired reception channel or frequency.

It will further be noted that the reflector rods resting in and firmly pressed against the ends of the slots 24,- 25 by means of the springs are grounded by virtue of their connection with the member '10 which is attached to the mast 3B.

' The operation of the device has already been described and it will be clear that for transportation purposes the reflector and dipole antenna rods are folded and are held within the hollow interior of the member Hi the position shown in Figures 2 and 3. The whole structure is then housed within the member ID which is easily portable. When the antenna is to be mounted the whole manipulation consists in unscrewing the wing nut and in moving the spindle along the slots. During this operation the rods will spread and are moved angularlyand when they finally reach the end points and are aligned they may be fixed in the slots by the wing nuts which are again tightly screwed down. The entire structure is now ready for operation.

It will also be clear that a number of unessential details may be changed or replaced by other details without departing from the essence of the invention as defined by' the annexed claims.

Having described the invention, what is claimed as new is:

1. A dipole antenna structure comprising hinged foldable dipole rods, a spindle forming the pivot of the hinge, an insulating sleeve around said spindle, a hinge member provided with eyes connected with each of said dipole rods surrounding said insulating sleeve, an insulating disk between the hinge members of the dipole rods, and further insulating disks on the outwardly turned faces of the hinge members to insulate'the dipole rods from contact with other members and from each other, a hollow elongated supporting member provided with a longitudinal slot and with two further parallel slots near one end, said last named slots arranged in the same plane and being adapted to receive the dipole rods when aligned in their operative position and at right angles to the axis of the elongated supporting member, the aforesaid spindle projecting through the first named longitudinal slot and being movable within and along said slot from one end to the other, an insulating plate provided with a slot, surrounding each of the two further parallel slots, the slot in the insulated plate being narrower than but coincident with the slot in the supporting member, said insulating plates preventing contact of the dipole rods entering the end slots of the supporting member with the latter and insulating them in their operative position.

2. A dipole antenna as claimed in claim 1 wherein in addition the skits in the insulated plates are provided with enlargements forming rests for the dipole rods and springs facing said enlargements pressing the dipole rods entering into the slots into the rests.

3. A dipole antenna structure comprising hinged foldable dipole rods, a spindle forming the pivot of the hinge, an insulating sleeve around said spindle, a hinge member provided with eyes connected with each of said dipole rods surrounding said insulating sleeve, an insulating disk between the hinge members of the di pole rods, and further insulating disks on the outwardly turned faces of the hinge member to insulate the dipole rods from contact with other members and from each other, foldable hinged reflector rods, a spindle forming the pivot point of the hinge of the reflector rods, a hollow elongated supporting member provided with two longitudinal slots on opposite sides of the supporting member and further provided with two pairs of parallel slots, one pair at each end of the supporting member, each pair of slots being located in one plane, and the two pairs of slots at the two ends being located in different planes, each of the spindles of the hinged foldable dipole and reflector rods projecting through one of the two longitudinal slots of the supporting member and being movable in and along said slot from end to end, the further parallel slots near the ends of the supporting member being arranged to accommodate the dipole and the reflector rods respectively when aligned and in ther operative position with the spindle forming the hinge near one end of the longitudinal slot within which it moves, insulated plates provided with slots surrounding the further parallel slots near that end of the supporting member which accommodates the dipole rods, the slots in the insulating plates being narrower than, but coincident with the slots in the supporting member to insulate the dipole rods entering the slots from contact with said supporting member and springs near the ends of the further parallel slots on both ends of the supporting member to hold the rods in their operative position near the ends of the slots.

4. A dipole antenna structure comprising hinged foldable dipole rods, a spindle forming the hinge pivot of the dipole rods, hinged foldable reflector rods, a further spindle forming the hinge pivot of the reflector rods, a hollow elongated spacing and supporting member forming a cross-bar spacing the dipole rods and reflector rods and provided with two slots on opposite sides, each of the spindles projecting from and being slidable along one of said slots, said dipole and reflector rods in one end position of the spindle being aligned and positioned at right angles to the supporting member axis and in the other end position of the spindle being folded and withdrawn into and surrounded by the supporting member, spacing wedges arranged near the end of the supporting member on the same, with the edge of the wedge directed towards the interior of the supporting member, to deflect and spread the folded dipole and reflector rods when 6 moved along the supporting member into their operative position.

III

5. A dipole antenna structure comprising hinged foldable rod systems including foldable dipole rods, a guide spindle forming the hinge pivot of said dipole rods, hinged foldable reflector rods, and a further spindle forming the hinge pivot of the reflector rods, an elongated hollow supporting containing member with open ends substantially of a length smaller than the added lengths of a dipole and reflector rod when folded and of such cross section that the dipole rods and reflector rods are both housed and longitudinally movable within longitudinal portions of the hollow supporting container member, the said last named member being further provided with two longitudinal parallel guide slots on opposite sides of the container member, running along the entire container member from a point near one end to a point near the other end, through which slots the guide spindles of the dipole rods and reflector rods project towards the outside of the container, the said slots thus guiding the spindles of the dipole rods and the reflector rods respectively during a longitudinal movement of the said rods, moving them from an operative position into a folding position in the interior of the container member, each end of the said hollow container member being further provided with a pair of short parallel guiding and seating slots, the slots of each pair being arranged on opposite sides of the hollow supporting container member and reaching from the open end towards a point near the end of the longitudinal slots of the hollow container member, the axes of said short guiding and seating slots being arranged in the plane of movement of the axes of the dipole rods and of the reflector rods, respectively, the end of each of said short guiding and seating slots seating the dipole and reflector rods respectively in their operative position and guiding the folding movement of the said dipole and reflector rods when their spindles are moved along the longitudinal guiding slots, each pair of foldable rods during such folding movement moving independently of the other pair within its separate longitudinal portion of the hollow container member, the said spindles being further provided with means for holding each pair of rods within its longitudinal portion of the container member and further means for fixing the spindle in the end positions near the ends of the longitudinal slots.

GERALD G. WENTW'ORTH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,042,931 Ewen June 2, 1936 2,465,331 Resnick Mar. 22, 1949 2,521,798 Leonard Sept. 12, 1950 2,542,137 Hanson Feb. 20, 1951 2,556,839 Cretella June 12, 1951 FOREIGN PATENTS Number Country Date 495,019 Great Britain Nov. 4, 1938 15,492 Switzerland Oct. 16, 1897 

